Improvement of longitudinal wave generation of elctrodynamic transducers

Basic improvements in the generation of longitudinal waves in electrical conducting materials are studied, being of importance in testing by contactless ultrasonic techniques. An optimum of sound generation and detection is achieved, when printed coils, which are packed in stacks, are applied, when the high frequency circuits are adapted and when the magnetic field is conducted almost parallel into the surface by means of a new magnet design. Significantly higher signals result and widen the applicability of this method in the field of nondestructive testing. (orig.)